Internet connection speed slow

I have a Motorola Arris SB6141, DOCSIS 3.0 modem.  In the beginning, when I first upgraded my Internet service from Internet Preferred to Internet Premier, I had average upload speeds of 98mbps,and 6mbps Upload.  Nothing has changed on my end.  Now I'm lucky to get average of 52mbps Download and 5mbps Upload speeds.  What has happened?  If I can't get anything better than 50mbps download, then I think I want to change my Internet service back from the Premier service to the Preferred service.  Please advise.

Thank you,

Steve

Steve Wong

sjwong55@cox.net